Networks are made of many types of equipment and technologies, therefore, it follows two popular standards – the OSI model and Internet Model. A network fall under 3 different categories – LAN, WAN, and MAN.
Before we jump into the computer models, know that computer networks fall under certain categories depending on their geographical size.
Local Area Network (LAN)
A local area network (LAN) is a privately owned network that links offices, a building, or a campus. The LAN is limited to a few kilometers. It can be a simple network with 2 computers and a printer or it can span an entire company with computers that has audio/video peripherals.
LANs are used for resource sharing among PCs, that shared printer(hardware) or software (application). Another model is the client-server model where a single computer with more disk space configured to be server and other computers in LAN are clients. The network is restricted due to license by a user per software installation or user licensed by access to OS.
LAN uses special types of transmission medium and topology such as bus, ring, and star. Speed of LAN nowadays has increased to 100 Mbps to 1 Gbps.
Wide Area Network
Wide Area Network (WAN) performs long-distance transmission of data over large geographical areas such as countries, continents, and the whole world.
There are two types of WAN network – Switched WAN and point-to-point WAN. The switched WAN connects two networks with a router. One of the networks (LAN or WAN) connects to another LAN or WAN system. The point-to-point WAN is a lease-line that connects a LAN or a home computer to an internet service provider (isp) who provides internet access.
Metropolitan Area Network (MAN)
This spans a few kilometers between LAN and WAN networks. The MAN covers a city or a town. For example, telephone companies that provide high-speed DSL line for the internet to their customers use MAN. Cable TV originally intended for tv is used for internet connection is a MAN network.